import os

def q01():
    a01 = [1, 3, 5, 7, 0, -1, -9, -4, -5, 8]
    z01 = []
    f01 = []
    for i in a01:
        if i > 0:
            z01.append(i)
        elif i < 0:
            f01.append(i)
    z02 = len(z01)
    f02 = len(f01)
    print(('有%s个正数；%s个负数。' %(z02,f02) ))

def q02():
    s01 = 'axbyczdj'
    s02 = s01[::2]
    print(s02)

def q02_2():
    s01 = 'axbyczdj'
    s02 = s01[1:-1:2]
    print(s02)
def q02_3():
    s01 = 'axbyczdj'
    s02 = s01[-1:-7:-1]
    print(s02)

def q03():
    s01 = 'hello_world_yoyo'
    s02 = s01.split('_')
    print(s02)
def a01():
    print('***获取当前目录***')
    print(os.getcwd())
    print(os.path.abspath(os.path.dirname(__file__)))
    print('***获取上级目录***')
    print(os.path.abspath(os.path.dirname(os.path.dirname(__file__))))
    print(os.path.abspath(os.path.dirname(os.getcwd())))
    print(os.path.abspath(os.path.join(os.getcwd(), "..")))
    print('***获取上上级目录***')
    print(os.path.abspath(os.path.join(os.getcwd(), "../..")))
def a02():
    print(range(1,2))
def a03():
    l01 = [1,2]
    l02 = ['a']
    a,a01 = l01
    b = l02
    return a

if __name__ == '__main__':
    print(a03())